Orientational alignment in a dilute dispersion of kaolinite particles has been investigated in a flow pattern that combines both shear and elongational stress, namely flow at a jet created by a 2 mm diameter nozzle inserted in a 6 mm diameter pipe. Spatially-resolved X-ray diffraction with synchrotron radiation permits detailed maps of the alignment to be deduced and compared with fluid mechanics calculations of the flow. The angular distribution of diffracted intensity from a given position in the pipe provides information about the orientation distribution of the particles. This is quantified and presented in terms of order parameters. The cone-shaped nozzle provides a jet of liquid giving a high degree of alignment of the particles that is uniform along lines across the conical section and constant in the small straight-sided region at the exit of the nozzle. The vortex motion that arises from the flow with a modest Reynolds number could be determined as well as the tendency for some particles to align with their large faces perpendicular to the overall flow direction at the flat surface of the nozzle outlet.
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http://dx.doi.org/10.1021/la204864p | DOI Listing |
Sensors (Basel)
January 2025
School of Mechanical, Aerospace & Civil Engineering, University of Sheffield, Sheffield S1 3JD, UK.
Stress wave dispersion can result in the loss or distortion of critical high-frequency data during high-strain-rate material tests or blast loading experiments. The purpose of this work is to demonstrate the benefits of correcting stress wave dispersion in split-Hopkinson pressure bar experiments under various testing situations. To do this, an innovative computational algorithm, SHPB_Processing.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
School of Civil Engineering, Southwest Jiaotong University, Chengdu, Sichuan Province 610031, China.
Chemical weathering of lithologies with high geochemical backgrounds such as black shale has been proposed to be a critical source for toxic elements in soil and water systems. However, mechanisms controlling the release, migration and enrichment of toxic elements during black shale weathering are poorly understood. This study utilized a suite of micro analytical techniques such as TESCAN integrated mineral analyzer (TIMA), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS) and electron micro-probe analysis (EMPA) to elucidate the intimate relationship between mineralogical transformations and elemental behaviors from profile scale to mineral scale.
View Article and Find Full Text PDFPolymers (Basel)
November 2024
Faculty of Mechanics, University Politehnica of Timisoara, 2 Piata Victoriei, 300006 Timisoara, Romania.
This study investigates the synthesis and characterization of acrylic resin/kaolin composites for dielectric applications. Acrylic resin, while widely used for its mechanical strength and ease of processing, exhibits limited dielectric properties, which restrict its use in high-performance electrical insulation. To address this, varying concentrations (0-70%) of raw kaolin, containing 71% kaolinite, were incorporated into an acrylic resin matrix to enhance its dielectric strength and thermal stability.
View Article and Find Full Text PDFACS Omega
December 2024
Chemistry Department, College of Science, Bahir Dar University, PO Box 79 Bahir Dar, Ethiopia.
Water contamination by nitro compounds from various industrial processes has significantly contributed to environmental pollution and severely threatened aquatic ecosystems. Inexpensive, efficient, and environmentally benign catalysts are required for the catalytic reduction of such nitro compounds. This study reports the fabrication of various nanocomposites (NCs) of copper oxide nanoparticles (CuO NPs) supported on a kaolin sheet using straightforward and simple one-pot synthesis procedures that control the metal precursor to kaolin ratios.
View Article and Find Full Text PDFSci Total Environ
December 2024
School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, PR China. Electronic address:
CO saline aquifer storage represents a promising strategy for mitigating the environmental impact of greenhouse gas emissions. However, the long-term effects of CO dissolved in formation water on rock minerals remain insufficiently understood. This study utilizes cast thin section analysis, scanning electron microscopy, and energy dispersive spectrometry techniques to perform a comprehensive microscopic investigation on this issue.
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